ALAMEDA, Calif. -- When Darren McFadden burst through a hole in the Denver defense two weeks ago and outraced the Broncos for a 59-yard touchdown, there was a huge sense of relief.

"I always tell myself, when I go into a football season, when I get that first big run, it will be a big weight off of my shoulders," McFadden said. "It seems like it's been three years since I have been able to get that weight off my shoulders."

After two disappointing seasons that raised questions whether McFadden would be the latest in a line of first-round draft busts for the Oakland Raiders, he has finally arrived as a big-time NFL running back.

McFadden leads the league with 111.3 yards rushing per game, has been a threat catching the ball out of the backfield, and has scored six touchdowns in six games.

His performance the first half of the season has quieted the critics and been a major reason for the improved play from the Raiders (4-4), who are .500 or better this late in the season for the first time since their 2002 Super Bowl campaign.

"I just wanted to get out there and get back on top of things this year," he said. "It ate at me a whole lot. That's why I am going out there and trying to play as hard as I can. I am doing the best I can and trying to get better every game."

The two-time Heisman Trophy runner-up had gone from one of the most dynamic runners in recent years in college football to an unproductive, injury-plagued professional in his first two seasons with Oakland.

He spent the offseason training with Olympic sprinter Michael Johnson and cutting junk food out of his diet. The changes have been evident on the field.

"I think he's taken some heat," coach Tom Cable said. "Some things have been written and said about him with the media and that's your job, that's what you do. But I think when anyone gets questioned, good character looks in the mirror and says, 'Is this really me?' and, 'If it is, I got to change.' Then you kind of use all that crazy stuff that gets said or written and you use it as fuel and I think he's done that."

While outsiders questioned whether McFadden would ever make it as a big-time back, the Raiders remained confident in the player they drafted fourth overall in 2008. Coaches and teammates kept preaching that all it would take for McFadden to be successful was good health after injuries to his toes, shoulder and knee hampered the start of his career.

"Anytime I have gotten a question about, 'Is Darren all hype? Or can he live up to the hype?' I tell them, 'Just watch. Just watch,"' fullback Marcel Reece said. "I already knew it was coming. Once Darren got healthy, once he got confident in this scheme, just watch. He's going to run away with it. I knew it, Darren knew it, this organization has known it, obviously, and now the rest of the world is getting to see it. It's exciting."

McFadden rushed for just 856 yards in 25 games, seeing his average per carry drop from 4.4 as a rookie to 3.4 last season. That's a far cry from the game-breaking back the Raiders were counting on when they picked McFadden so high. He scored just one touchdown last season and had only one run of at least 20 yards since the second game of his rookie year.

But now the Raiders are seeing the McFadden they saw in college at Arkansas, when he ran for 41 touchdowns in three seasons, including nine that went for at least 50 yards. He longest touchdown run as a pro before this year was 19 yards.

He has seven runs of at least 20 yards this season, including the long score against Denver that capped a four-touchdown day.

"As a player if you think people are down on you and you've been doing good for a long time, it probably tends to get on your nerves," teammate Michael Bush said. "At the same time, he's a competitor. He's very competitive and he's out there to prove people wrong. That's what drives a lot of athletes, people talking down on you or negative about what you do. That makes you go out there and play much harder."

The biggest question McFadden answered has been about his ability to grind out the tough yards. Most of McFadden's success his first two seasons came when the Raiders got him out in space, often when he was lined up as a wide receiver.

More than a quarter of his runs have come up the middle this season, according to STATS LLC, and he is averaging 6.1 yards on those 33 carries. He averaged just 3.5 yards per carry on runs up the middle his first two seasons.

More than half his yards on the ground this season have come after initial contact, an improvement from his first two seasons.

"A lot of people said that, but I always knew what I could do," he said. "Running past them, running around them or through them, they're all on the same page for me. However I can get to the next yard line."